Cut a cardboard box to fit window. Paint it black with spray can. Duct tape from inside. Order window from Airstream after trip. Enjoy the rest of your trip. That's what I would do. Bar harbor at night. Thunder hole, having lunch outside at the only restaurant in the park, walk around the lake to work off lunch... 2 hr walk. Almost forgot, blueberry pancakes in the morning in Bah Harbor. Don't sweat the small stuff... Accidents happen to all of us.
Welcome to the forum hedgley